According to statistics, more than 4 million cases of surgery are performed every year in the world. The hemostasis and antisepsis of the wound are key operations in surgery, especially when the operation need sew and ligate for repairing the tissue of organism. However, the operation is not only tedious, laborious, time-consuming, but also easy to cause new damage, bleeding and bring about more pain to the patient. For large areas of bleeding in which bleeding spots can't be found, doctors feel helpless, while the emergence of medical adhesive with fast hemostasis, sealing and adhesion functions provides a solution for solving the above problems.
Medical adhesive generally refers to the cyanoacrylate tissue adhesive, which mechanism of action is thought of as anions polymerization in presence of trace anions in wound blood and tissue fluid, and the resulted elastic thin adhesive film which shows high tensile strength. The adhesive film is observed as a network structure under electron microscope, which can effectively block the hemoglobin and platelet to achieve desired effect of hemostasis, adhesion and sealing. First cyanoacrylate adhesive on reported can be traced back to 1959, methyl cyanoacrylate (Eastman910) was developed by the United States Eastman Kodak company, and the product immediately attracted the attention of the medical profession for its instant adhesive property. Later homologous series of cyanoacrylate were synthesized including the ethyl cyanoacrylate, n-butyl cyanoacrylate, n-octyl cyanoacrylate, ethoxy ethyl cyanoacrylate, ethoxy butyl cyanoacrylate, ethoxy octyl cyanoacrylate, butyl lactyl cyanoacrylate, isooctyl lactyl cyanoacrylate etc. Cyanoacrylate adhesive shows some advantages, such as simple composition, easy use, fast solidification at room temperature, and high bonding strength, so it can be applied in many fields including the medical field. The cyanoacrylate medical adhesive has been widely used in clinic, including the main use field of adherence of incisions and wounds on the body surface, closed hemostasis of the body organ section as well as esophageal and fundal varices and vascular embolization.
The chemical structure of cyanoacrylate compounds commercially available at present can be expressed by formula I:

1) R can be a linear, branched or cyclic alkyl group with 1-20 carbon atoms;
or, 2) R can also be a group of formula —R2—O—R3, in which R2 and R3 are linear, branched or cyclic alkyl groups with 1-20 carbon atoms respectively and independently.
or, 3) R can be a group of formula —R4—COO—R5, in which R4 and R5 are linear, branched or cyclic alkyl groups with 1-20 carbon atoms respectively and independently.
According to different ester parts, the formula I cyanoacrylate compound can be divided into: 1) alkyl cyanoacrylate; 2) alkoxy cyanoacrylate; 3)lactyl cyanoacrylate. Alkyl cyanoacrylate and alkoxy cyanoacrylate products have the advantages of fast bonding rate and high bonding strength, but in clinical applications especially in vivo applications, these two products have their own shortcomings, namely the stable chemical property of formed polymer and the deficiency of enzymes for effectively decomposing the polymer, which lead to these two kinds of polymer present in the body for a long time as a foreign body (or implants) and bring some risk to the patient. The alkyl cyanoacrylate product also has the disadvantage of hard adhesive film. Compared with alkyl cyanoacrylate and alkoxy cyanoacrylate, lactyl cyanoacrylate product is better in degradation and biological compatibility, especially faster in degradation rate, and more secure in vivo medical uses, while the bonding rate and bonding strength of lactyl cyanoacrylate have weakness.
In order to improve the degradation rate of alkyl cyanoacrylate, scientists both at home and abroad have done a lot of attempts. For example, the alkyl cyanoacrylate and lactyl cyanoacrylate were mixed in a certain proportion, and two monomers were copolymerized in situ to form copolymers in practical application. Because polymer fragment of the lactyl cyanoacrylate provides a degradable part for copolymer, the degradation rate of the copolymer was greatly improved, and due to more excellent biocompatibility of lactyl cyanoacrylate, the product not only provides high bonding strength and good degradation rate, but also brings a better user experience. However, lactyl cyanoacrylate is very unstable, and is sensitive to acid and alkali and prone to hydrolysis for its lactyl structure, and hydrolysis products can further accelerate the polymerization of lactyl cyanoacrylate, so these products are very difficult to store for a long time at room temperature. Although low temperature facilities can be used to extend the storage period of lactyl cyanoacrylate medical adhesive, it will greatly increase the cost of production, storage and transportation, and will also bring additional risks.
To sum up, the prior arts of cyanoacrylate medical adhesive have defects, in clinical, medical adhesive with the features of a long-term storage, a rapid degradation rate, a rapid bonding rate, excellent bonding strength and excellent softness of adhesive film is needed. The purpose of the present disclosure is to provide cyanoacrylate medical adhesive which can be stored for a long time and has the features of a rapid degradation rate, a rapid bonding rate, excellent bond strength and softness of adhesive film.